JOSHUA TREE NATIONAL PARK >> As the country celebrated Independence Day with barbecues, family and fireworks on Friday, San Bernardino County sheriff’s deputies and search-and-rescue volunteers scoured the area for any sign of a missing pregnant woman.

Around 7 a.m. June 28, Erin left her Twentynine Palms home to find a camping spot in the national park, authorities said.

Her husband reported her missing the following day.

Sheriff’s officials fanned out across the area to try and find the woman, who was three months’ pregnant, but they fear foul play may be involved in her disappearance.

On Monday, deputies discovered her car parked and abandoned not too far from the entrance gate of the Marine Corps Air Ground Combat Center at Twentynine Palms.

People have come as far as Los Angeles to help in the search.

“We rock climb, hike and just simply love the outdoors,” Playa del Rey resident Nancy McCarthy said. “We figured we’d climb, hike and search alongside the deputies. There’s no harm in adding four more eyes and if it gets her back with her family then it’s worth it.”

Authorities have given no indication that Cpl. Corwin is considered a person of interest in their investigation.

The Marine Corps has forbidden Cpl. Corwin from speaking publicly about his wife’s disappearance, according to family members, but Erin’s sister-in-law said there is no way he is even capable of harming his bride.

“If you knew him you’d know how much he loves her and what kind of an exemplary man he truly is,” said DeeAnna Heavilin of Corpus Christi, Texas, in a phone interview. “God forbid, if harm did come to her it wasn’t from his hands.”